numPy gives nan while reading a negative number from a file

Question

I tried to read the contents of a 3x3 matrix stored in a text file having the following values.

−30  10  20  
 10  40 −50  
 20 −50 −10

I used numpy.genfromtxt as follows but when it gave nan in place of negative data values.

data = np.genfromtxt('file.txt',delimiter=' ')
print(data)
print(type(data[0][0]))

But the datatype of the negative value still shows float64:

I also tried reading the values as a list and then converting to numpy array but that also didn't work.

Is there any other way I can read negative values as a numpy array from a file input?

Please do not post text such as code, error messages, or data on SO, always post the text directly here on SO. — Mr. T, Sep 09 '18 at 06:50

score 4 · Accepted Answer · answered Sep 09 '18 at 06:20

4

You've got U+2212 MINUS SIGN characters in your file, not the U+002D HYPHEN-MINUS people usually think of as the minus sign character. genfromtxt doesn't handle that character. Replace the minus sign characters with hyphen-minuses before trying to parse the data.

answered Sep 09 '18 at 06:20

user2357112

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It worked. Thanks for the answer. I didn't know about this convention. – Ashutosh Kumar Sep 09 '18 at 10:27

score 1 · Answer 2 · answered Sep 09 '18 at 07:13

1

Try this code instead:

data=pd.read_csv("data.txt",delimiter=",")
data = DataFrame(data)

answered Sep 09 '18 at 07:13

Abo Omar

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I tried it and it works, you give me -1 without even try it ? – Abo Omar Sep 09 '18 at 07:47
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You don't know who downvoted your answer, so don't blame the OP. In fact, it is rather unlikely that it was the OP. – Mr. T Sep 09 '18 at 08:18
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I guess you got down vote because the OP's input data are NOT **comma** (`,`) delimited . – MarianD Sep 10 '18 at 22:16

numPy gives nan while reading a negative number from a file

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